我家母鸡生蛋了。 My hen laid eggs.

Clet told us that seems like our hen laid egg yesterday.  But he was unsure how many.  To allow the hen having more comfortable nest to hetch the eggs, Clet brought some dried grass home just now.  Upon checking on the nest there are a total of 9 eggs.  Our hen is very protective of her eggs just like a mother protecting her children.  She is very furious when our dog, Lucky,  barking at her when Clet put the dried grass into its nest.  We have to put Lucky to the front porch to calm her down.

Anyone knows how long does it take for a hen to hetch the eggs in order for the chicks to come out?